This invention relates to improvements in the manufacture of remote entry transmitters.
Modern vehicles are often provided with remote entry systems for unlocking the vehicle doors, locking the vehicle doors, unlocking the trunk, etc. from a distance. These devices are desirably made as small as possible. On the other hand, and contrary to the goal of making the transmitters small, it has become desirable to include more and more electrical features into the devices. In addition, the range of the devices is somewhat dependent on the size of the antenna associated with the transmitter. The antennas have typically been relatively long, and have been formed as part of a planar circuit board. Typically, the antennas wrap around the outer periphery of the circuit board, and are parallel to the other circuit traces.
Traditionally these remote entry devices are manufactured by forming two separate plastic housing elements, and sandwiching a circuit board between the two. Switches and other portions are then added to the device. This has required a large number of parts, and several assembly steps.
So-called two-shot molding techniques are known wherein devices are formed by utilizing different plastic materials. Two-shot molding has been proposed for forming electrical components, wherein a plateable and a non-plateable plastic are each molded at different stages in a plastic mold. The plateable material is then provided with a conductive molding to form electrical components. However, these methods have never been applied to remote entry systems.
In a disclosed embodiment of this invention, a two-shot molding technique is utilized to form one of the main housing components of a remote entry transmitter. The housing component can be integrally plated with circuit traces. This eliminates the need for a separate circuit board, and thus simplifies assembly.
Two-shot molding has typically not been utilized to provide an outer housing element which must have an aesthetically desirable appearance. Typically, the two-shot molding techniques have been for hidden elements. The present invention now utilizes the two-shot molding for an outer surface, which is distinct from the prior art. Moreover, the two-shot molding techniques have never been utilized for remote entry systems. Both of these are improvements over the prior art, and result in the reduction in the number of elements associated with the remote entry systems.
In another feature of this invention, the antenna is formed to extend generally perpendicularly to the main circuit board. This feature is separately distinct and patentable from the two-shot molding, although in one embodiment it is also incorporated into a two-shot molded system.
The antenna is most preferably molded along an inner wall of the housing member. Thus, the size and space that had previously been required for the antenna to extend parallel to the circuit board is no longer necessary. Instead, the antenna is now placed on a surface area, the sidewall, which had not previously been utilized for any electrical components. In this way, the size of the remote transmitter can be made smaller.
In a second embodiment, the antenna is formed on a separate board which is attached to the main circuit board, and which also extends perpendicularly to the main circuit board. More generally, this aspect of the invention is placing the antenna at a non-parallel angle to the plane of the circuit board.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.